// 主应用逻辑
class CalculusApp {
    constructor() {
        this.calculus = new CalculusEngine();
        this.chart = null;
        this.currentLanguage = 'zh';
        
        this.init();
    }

    init() {
        this.setupEventListeners();
        this.setupChart();
        this.loadLanguage();
    }

    setupEventListeners() {
        // 绘制按钮
        document.getElementById('plotBtn').addEventListener('click', () => {
            this.plotFunction();
        });

        // 微积分操作按钮
        document.getElementById('limitBtn').addEventListener('click', () => {
            this